Communication method between electric vehicle, supply equipment, and power grid operation server

ABSTRACT

A method of communicating between an electric vehicle, a supply equipment, and a power grid includes transmitting, by an electric vehicle communication controller of the electric vehicle, a discharge schedule including an amount of energy discharge, a discharge start time, and a discharge finish time to a supply equipment communication controller of the supply equipment or a power grid communication controller of the power grid operation server, and receiving a discharge cost calculated according to the discharge schedule from the supply equipment communication controller or the power grid communication controller, wherein the discharge cost including an additional calculation cost, in response to a sum of the amount of energy discharge of the electric vehicle and an amount of energy discharge of another electric vehicle being greater than or equal to a reference energy discharge amount.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119 to KoreanPatent Application No. 10-2020-0183874, filed on Dec. 24, 2020, in theKorean Intellectual Property Office, the entire disclosure of which isincorporated herein by reference for all purposes.

TECHNICAL FIELD 1. Field

The present invention relates to a vehicle-to-grid (V2G) communicationinterface.

BACKGROUND 2. Description of Related Art

V2G is an abbreviation of “vehicle to grid,” which is a term that meansthat an electric vehicle and a power grid are connected. Standardsrelated to V2G technology do not define specific communicationinterfaces related to a discharge schedule for an effective billingpolicy.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

In one general aspect, there is provided a method of communicatingbetween an electric vehicle, a supply equipment, and a power gridoperation server that monitors a power grid, the method includingtransmitting, by an electric vehicle communication controller of theelectric vehicle, a discharge schedule including an amount of energydischarge, a discharge start time, and a discharge finish time to asupply equipment communication controller of the supply equipment or apower grid communication controller of the power grid operation server,and receiving a discharge cost calculated according to the dischargeschedule from the supply equipment communication controller or the powergrid communication controller, wherein the discharge cost including anadditional calculation cost, in response to a sum of the amount ofenergy discharge of the electric vehicle and an amount of energydischarge of another electric vehicle being greater than or equal to areference energy discharge amount.

The method may include setting up the discharge schedule in the electricvehicle prior to the transmitting of the discharge schedule, wherein thesetting up of the discharge schedule including setting a discharge starttime and a discharge finish time on the basis of battery capacityinformation, battery voltage information, and state-of-chargeinformation.

The transmitting of the discharge schedule may include transmitting amessage for calculation of the discharge cost, to the supply equipmentcommunication controller of the supply equipment or the power gridcommunication controller of the power grid operation server on the basisof the sum of the amount of energy discharge of the electric vehicle andthe amount of energy discharge of the another electric vehicle.

The additional calculation cost may be varied based on the sum of theamount of energy discharge of the electric vehicle and the amount ofenergy discharge of the another electric vehicle.

The method may include transmitting an authorization message for thedischarge cost to the supply equipment communication controller or thepower grid communication controller using the electric vehiclecommunication controller, and transmitting a message, indicating that adischarge process is forcibly stopped, in response to the dischargeprocess being stopped prior to the discharge finish time by an user ofthe vehicle , to the supply equipment communication controller or thepower grid communication controller using the electric vehiclecommunication controller.

The method may include receiving, from the supply equipmentcommunication controller or the power grid communication controller, amessage indicating a return cost of a difference between a dischargecost calculated based on the discharge finish time and a discharge costcalculated when the discharge is forcibly stopped, in response to thedischarge process being forcibly stopped.

In another general aspect, there is provided a method of communicatingbetween an electric vehicle, a supply equipment, and a power gridoperation server that monitors a power grid, the method includingtransmitting, by a supply equipment communication controller embedded inthe supply equipment, a discharge cost based on a discharge schedule ofthe electric vehicle to an electric vehicle communication controllerembedded in the electric vehicle, transmitting a message related to anauthorization request for the discharge cost to the electric vehiclecommunication controller using the supply equipment communicationcontroller, and receiving, at the supply equipment communicationcontroller, an authorization message for the discharge cost from theelectric vehicle communication controller, wherein the discharge costincluding an additional calculation cost, in response to a sum of theamount of energy discharge of the electric vehicle and an amount ofenergy discharge of another electric vehicle being greater than or equalto a reference energy discharge amount.

The method may include setting up the discharge schedule in the supplyequipment prior to the transmitting of the discharge cost based on thedischarge schedule, wherein the setting up of the discharge schedule maybe based on battery capacity information, battery voltage information,and state-of-charge information received from the electric vehiclecommunication controller and a sales tariff table received from a powergrid communication controller of the power grid operation server.

The method may include setting up the discharge schedule in the supplyequipment prior to the transmitting of the discharge cost, wherein thedischarge schedule including the amount of energy discharge, a dischargestart time, and a discharge finish time.

The method may include, after the receiving of the authorization messagefor the discharge cost, transmitting, to the supply equipmentcommunication controller and a power grid communication controller ofthe power grid operation server, a message indicating that the dischargeprocess is forcibly stopped by an operator of the supply equipment.

The method may include transmitting, from the electric vehiclecommunication controller or the power grid communication controller, amessage indicating a return cost of a difference between a dischargecost calculated based on the discharge finish time and a cost calculatedbased on a finish time when the discharge is forcibly stopped, inresponse to the discharge process being forcibly stopped.

The method may include calculating an amount of carbon dioxide reductionon the basis of the amount of energy consumption of an off-board chargerof the supply equipment using the supply equipment communicationcontroller, and transmitting information related to the amount of carbondioxide reduction to the electric vehicle communication controller andthe power grid communication controller.

Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall configuration diagram of a vehicle-to-grid (V2G)system according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a local communication connectionbetween an electric vehicle communication controller and a supplyequipment communication controller using the open systemsinterconnection (OSI) layers according to an embodiment of the presentinvention.

FIG. 3 is a diagram illustrating a remote communication connectionbetween an electric vehicle communication controller and a supplyequipment communication controller using the OSI layers according toanother embodiment of the present invention.

FIG. 4 is a diagram illustrating a communication connection between asupply equipment communication controller and a power grid communicationcontroller using the OSI layers according to still another embodiment ofthe present invention.

FIG. 5 is a flowchart illustrating a discharge scenario according to anembodiment of the present invention.

FIG. 6 is a sequence diagram of messages exchanged between an electricvehicle, a supply equipment, and a power grid operation server on thebasis of a discharge scenario according to an embodiment of the presentinvention and also is a sequence diagram in the case of setting up adischarge schedule in the electric vehicle.

FIG. 7 is a sequence diagram between an electric vehicle, a supplyequipment, and a power grid operation server according to anotherembodiment of the present invention and also is a sequence diagram inthe case of setting up a discharge schedule in the supply equipment.

Throughout the drawings and the detailed description, unless otherwisedescribed or provided, the same drawing reference numerals will beunderstood to refer to the same elements, features, and structures. Thedrawings may not be to scale, and the relative size, proportions, anddepiction of elements in the drawings may be exaggerated for clarity,illustration, and convenience.

DETAILED DESCRIPTION OF EMBODIMENTS

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. However, various changes,modifications, and equivalents of the methods, apparatuses, and/orsystems described herein will be apparent after an understanding of thedisclosure of this application. For example, the sequences of operationsdescribed herein are merely examples, and are not limited to those setforth herein, but may be changed as will be apparent after anunderstanding of the disclosure of this application, with the exceptionof operations necessarily occurring in a certain order. Also,descriptions of features that are known may be omitted for increasedclarity and conciseness.

The features described herein may be embodied in different forms, andare not to be construed as being limited to the examples describedherein. Rather, the examples described herein have been provided merelyto illustrate some of the many possible ways of implementing themethods, apparatuses, and/or systems described herein that will beapparent after an understanding of the disclosure of this application.

The terminology used herein is for the purpose of describing particularexamples only and is not to be limiting of the examples. The singularforms “a”, “an”, and “the” are intended to include the plural forms aswell, unless the context clearly indicates otherwise. It will be furtherunderstood that the terms “comprises/comprising” and/or“includes/including” when used herein, specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components and/or groups thereof.

When describing the examples with reference to the accompanyingdrawings, like reference numerals refer to like constituent elements anda repeated description related thereto will be omitted. In thedescription of examples, detailed description of well-known relatedstructures or functions will be omitted when it is deemed that suchdescription will cause ambiguous interpretation of the presentdisclosure.

Also, in the description of the components, terms such as first, second,A, B, (a), (b) or the like may be used herein when describing componentsof the present disclosure. These terms are used only for the purpose ofdiscriminating one constituent element from another constituent element,and the nature, the sequences, or the orders of the constituent elementsare not limited by the terms. When one constituent element is describedas being “connected”, “coupled”, or “attached” to another constituentelement, it should be understood that one constituent element can beconnected or attached directly to another constituent element, and anintervening constituent element can also be “connected”, “coupled”, or“attached” to the constituent elements.

The present invention is applicable to communication between an electricvehicle (EV2) and an electric vehicle supply equipment (EVSE).

In addition, the present invention is also applicable to electricvehicles used for carriage of passengers, electric vehicles used forcarriage of goods, and electric vehicles of other categories.

Also, the present invention is applicable to high-level communication(HLC) related to conductive and wireless power transfer technologies.

Also, the present invention is applicable to technical fields in whichenergy is transferred from an EVSE to an EV to charge a battery of theEV and in which energy is transferred from an EV to an EVSE so that theenergy can be supplied to homes, loads, or grids.

Also, the present invention is applicable to technical fields related tocharge or discharge control, payment, load leveling, and privacy.

Definition of Terms

Electric Vehicle Communication Controller (EVCC)

An EVCC is an in-vehicle system that implements communication between anEV and a supply equipment communication controller (SECC) in order tosupport specific functions.

These specific functions include input and output channel control,encryption, data transfer between a vehicle and an SECC, and the like.

Supply Equipment Communication Controller (SECC)

An SECC is an entity capable of communicating with one or multiple EVCCsand interacting with a secondary actor.

Electric Vehicle Supply Equipment ID (EVSE ID)

An EVSE ID is a unique ID of a charging place.

Secondary Actor

A secondary actor is an entity that is indirectly involved in an energytransfer process including a charge process and a discharge schedule.

The secondary actor may include, for example, an electric vehicleservice operator information management office (E-Mobility OperatorClearing House), a demand information management office (Demand ClearingHouse), an electric vehicle operator (Fleet Operator), an electricvehicle service operator (E-Mobility Operator), a distribution systemoperation (Distribution System Operator), an electricity meter operator,an electric provider, and the like.

Examples of the secondary actor are defined in detail in ISO 15118-1.

Payment Unit

A payment unit is an internal device of a supply equipment that providesa payment method. Here, the payment method may be externalidentification means (EIM), cash, credit card, etc. Here, the EIM refersto an external means that allows a vehicle user to identify his or hercontract or EV and may include, for example, near field communication(NFC), radio-frequency identification (RFID), short message service(SMS), and so on.

When an EVCC normally selects a payment method, the payment unit informsan SECC of whether a customer is authorized.

Amount of Energy Charge

The amount of energy charge may be energy required for an EV untildeparture time is reached. The amount of energy charge may be, forexample, energy at which the state of charge (SOC) of a vehicle batteryis equal to 100% or close to 100% (e.g., 80%). Here, the departure timemay be the time when a vehicle user unplugs a vehicle's charging plug orthe time when a vehicle user leaves a charging station.

Amount of Energy Discharge

The amount of energy discharge may be defined as energy transferred froman EV to an EVSE or to a power grid via an EVSE according to a targetvalue or a discharge schedule set up by a user.

Vehicle User

A vehicle user may be defined as an individual or legal entity that usesa vehicle and provides information necessary for driving and thusinfluences a charging pattern and/or a discharging pattern.

Authentication

Authentication is a procedure performed between an EVCC and an SECC orbetween a vehicle user and an EVSE or a secondary actor in order toprove whether provided information (ID, etc.) is correct and valid orwhether provided information belongs to an EVCC, a vehicle user, and anSECC.

Service Provider

A service provider may be defined as a secondary actor that providesvalue-added services to customers through an operator of an EVSE.

Authorization

Authorization may be defined as a procedure in which an EVSE checkswhether an EV is authorized to be charged or discharged or vice versa.

Charger

A charger may be defined as a power conversion device that performsessential functions for charging and discharging batteries.

Charge schedule

A charge schedule may be defined as a plan including charging limits ofan EV for a specific period of time. A charge schedule may be an energytransfer schedule related to energy transferred from a power grid to anEV.

Charging Limits

Charging limits may be defined as physical constraints (e.g., voltage,current, energy, and power) negotiated for a charging session during aV2G communication session.

Charging Session

A charging session may be defined as a period of time between the start(cable connection) and the end (cable disconnection) of a chargeprocess.

Discharge schedule

A discharge schedule may be defined as a plan including discharginglimits of an EV for a specific period of time. A discharge schedule maybe an energy transfer schedule related to energy transferred from an EVto a power grid.

Battery Management System (BMS)

A BMS may be defined as an electronic apparatus that controls or manageselectrical and thermal functions of a vehicle battery and providescommunication between the vehicle battery and another vehiclecontroller.

Discharging Limits

Discharging limits may be defined as physical constraints (e.g.,voltage, current, energy, and power) negotiated for a dischargingsession during a V2G communication session.

Discharging Session

A discharging session may be defined as a period of time between thestart (cable connection) and the end (cable disconnection) of adischarge schedule.

Grid Schedule

A grid schedule may be defined as a function of setting a power level ata specific time based on a local grid situation. Parameters forcalculating the grid schedule may include, for example, an actual orpredicted demand and supply situation of a local grid.

Identification

Identification may be defined as a procedure in which an EVCC or a userprovides identification information (identification code) forauthentication or a procedure in which an SECC provides an EVSE ID to anEVCC.

Sales Tariff Table

A sales tariff table is used to provide an input value for calculating acharge schedule and/or a discharge schedule. A sales tariff table may beissued by a secondary actor, such as an electric provider and anelectric vehicle service operator. A sales tariff table reflects the“balance of supply and demand of an electric provider” and the “use ofgreen energy.” A sales tariff table may be regularly updated.

Electric Provider

An electric provider is a secondary actor that supplies electricity.

Hereinafter, embodiments of the present invention will be described indetail with reference to the drawings.

FIG. 1 is an overall configuration diagram of a vehicle-to-grid (V2G)system according to an embodiment of the present invention.

Referring to FIG. 1, a V2G system 500 according to an embodiment of thepresent invention provides a communication interface related to adischarge schedule for an effective billing policy.

To this end, the V2G system 500 includes an electric vehicle (EV) 100,an electric vehicle supply equipment (EVSE) 200, and a power gridoperation server 300.

Electric Vehicle (EV) 100

The EV 100 may be a battery-electric vehicle (BEV) or a plug-in hybridelectric vehicle (PHEV).

The EV 100 includes a vehicle battery 110, an on-board charger (OBC)120, an electronic control unit 130, a human-machine interface (HMI)140, an electric vehicle communication controller (EVCC) 150, and abattery management system (BMS) 160.

The vehicle battery 110 is a high-voltage battery installed in the EV100 and may be referred to as a rechargeable energy storage system(RESS).

The OBC 120 may be configured to include a power conversion deviceinstalled in the EV 100. The power conversion device may be a two-waycharger that performs an essential function for charging and dischargingthe vehicle battery 110.

The OBC 120 may exchange commands and/or information related to thecharging or discharge schedule with the EVCC 150.

The OBC 120 may be configured to further include a control chip having adata processing function (including a processor, a memory, etc.) so asto exchange the information and/or commands with the EVCC 150.

Moreover, FIG. 1 shows that the EVCC 150 and the OBC 120 are separatedfrom each other, but the EVCC 150 may be consolidated into the OBC 120.In this case, the OBC 120 may be configured to include the powerconversion device, the control chip, and the EVCC 150.

The electronic control unit 130 may be a unit that provides informationrelated to the EV 100. The information related to the EV 100 may bevehicle driving-related information.

The HMI 140 may have an interfacing function for displaying informationrelated to the charging or discharge schedule and inputting informationand/or commands related to the charging or discharge schedule.

The input of all the information and/or commands and the display of allthe information and/or commands may be performed through the HMI 140.

The HMI 140 may be configured to include a “charge button” and a“discharge button” for a vehicle user to start the charging or dischargeschedule.

The HMI 140 may be a display device having an input function for avehicle user to input the information related to the charging ordischarge schedule.

For example, the display device may be a central information display(CID) that has a cluster informing about the velocity, mileage, batterystatus, and normal operation of the EV 100 and audio, video, andnavigation (AVN) functions embedded therein to display and control theoperation states of various devices in the EV 100.

The EVCC 150 may be an in-vehicle system that implements communicationbetween the EV 100 and a supply equipment communication controller(SECC) 230 so as to support specific functions.

The communication between the EVCC 150 and the SECC 230 may be, forexample, power line communication (PLC) communication. It is assumedthat the term “electric vehicle” used herein refers to an electricvehicle with a PLC function.

The PLC may be referred to as power-line carrier, mains communication,power-line telecom (PLT), or power-line networking (PLN).

The PLC may be used as a term to describe several different systems forcarrying information over power lines.

The EVCC 150 may be configured to include a memory, a processor, and acommunicator.

The memory includes a volatile and/or non-volatile storage medium forstoring messages related to the charging or discharge schedule based ona protocol agreed with the SECC 230.

The processor processes messages received from the SECC 230 or processesmessages to be transmitted to the SECC 230.

The communicator may be a hardware element configured to transmit amessage related to the charging or discharge schedule to the SECC 230 orreceive a message related to the charging or discharge schedule from theSECC 230 on the basis of an agreed communication method, e.g., PLC. Thecommunicator may include multiple hardware components for providingmodulation, demodulation, filtering, and amplification functions.

The EVSE 200 may be a device configured to deliver energy (e.g., power,voltage, current, or the like) from the premises wiring to the EV 100and receive energy (e.g., power, voltage, current, or the like) from theEV 100.

The EVSE 200 may be configured to include a phase(s), neutrals,protective earth conductors, EV couplers, attached plugs, accessories,power outlets, electrical outlets or appliances, and the like.

The EVSE 200 may be configured to include an off-board charger 210, anHMI 220, an SECC 230, and a payment unit 240.

The off-board charger 210 may be configured to include a powerconversion device installed in the EVSE 200. The power conversion devicein the off-board charger 210 may be a two-way charger that transfersenergy to the OBC 120 installed in the EV 100 or receives energy fromthe OBC 120.

From the standpoint of the off-board charger 210, transferring energy tothe OBC 120 indicates charging, and receiving energy from the OBC 120indicates discharging. From the standpoint of the EV, discharging istransferring energy to an off-board charger and thus indicateselectricity generation. Gen included in a message symbol shown in FIGS.6 and 7 is an abbreviation of “generation.”

The off-board charger 210 exchanges commands and/or information relatedto the charging or discharge schedule with the SECC 230. To this end,the off-board charger 210 may be configured to further include a controlchip that processes commands and/or information transmitted to the SECC230 or received from SECC 230. The control chip may be configured tobasically include a processor and a memory mounted on one board.

FIG. 1 shows that the off-board charger 210 and the SECC 230 areseparated from each other, but the SECC 230 may be built in theoff-board charger 210. In this case, the off-board charger 210 may beconfigured to include the power conversion device, the control chip, andthe SECC 230.

The HMI 220 has an interfacing function for displaying the commandsand/or information related to the charging or discharge schedule andinputting the commands and/or information to the off-board charger 210or the SECC 230 of the EVSE 200.

The input of all the information and/or commands and the display of allthe information and/or commands may be performed through the HMI 220.

The HMI 220 may be configured to include a “charge button” and a“discharge button” for a vehicle user to input commands and/orinformation related to a charge or discharge schedule and a charging ordischarge schedule.

The HMI 220 may be a display device having an input function for avehicle user to input commands and/or information related to the chargeor discharge schedule and a charging or discharge schedule.

The SECC 230 is an entity capable of communicating with one or multipleEVCCs and interacting with a secondary actor.

Examples of the secondary actor have been described in the “Definitionof Terms” section. In FIG. 1, the power grid operation server 300 may beincluded in the secondary actor.

FIG. 1 shows one-to-one communication between one SECC 230 and one EVCC150. The present invention is not limited thereto, and when one SECC 230communicates with multiple EVCCs, the SECC 230 manages the multipleEVCCs and recognizes the clusters of the outlets to which the EVCCs areconnected.

The SECC 230 may be configured to include a memory, a processor, and acommunicator.

The memory may be a volatile or non-volatile storage medium for storingmessages related to the charging or discharge schedule on the basis of acommunication protocol (communication standard) agreed with the EVCC150.

The processor processes messages received from the EVCC 150 or processesmessages to be transmitted to the EVCC 150.

The communicator may be a hardware element configured to transmit amessage related to the charging or discharge schedule to the EVCC 150 orreceive a message related to the charging or discharge schedule from theEVCC 150 on the basis of an agreed communication method, e.g., PLC. Thecommunicator may include multiple hardware components for providingmodulation, demodulation, filtering, and amplification functions.

The SECC 230 may communicate with the power grid operation server 300.In this case, a gateway, a router, and the like may be interposedbetween the SECC 230 and the power grid operation server 300.

The SECC 230 may transmit or receive any information and/or commandrelated to the charging or discharge schedule to or from the power gridoperation server 300.

The power grid operation server 300 mediates between the SECC 230 andthe power grid 400. The power grid 400 may be configured to includelocal transformers, distribution grids, power substations, transmissiongrids, transmission substations, and power plants (including renewableenergy).

The power grid operation server 300 may be an entity for gridnegotiation that provides information on the load of the grid.

The power grid operation server 300 collects and monitors any necessaryinformation for any parts of the power grid 400, for example, currentand expected loads of local transformers, distribution grids, powersubstations, transmission grids, transmission substations, and powerplants.

The collected current load or expected load is utilized for the EV 100or the EVSE 200 to set up a charge or discharge schedule.

The power grid operation server 300 may provide information required bythe EVCC 150 or the SECC 230 to set up the charge or discharge scheduleto the EVCC 150 or the SECC 230.

The collection and provision of the information performed by the powergrid operation server 300 may be performed by a power grid communicationcontroller (PGCC) 310.

The PGCC 310 is configured to include a memory configured to storeinformation collected from the power grid 400 and information collectedfrom the EV 100 and/or the EVSE 200, a processor having a dataprocessing function to process the collected information, and acommunicator configured to transmit the processed information to theSECC 230.

An HMI 320 of the power grid operation server 300 displays informationcollected by the power grid operation server 300 and deliversinformation input by an operator of the power grid operation server 300to the PGCC 310.

The HMI 320 may be a display device, and the display device has an inputfunction. The display device displays and provides any collectedinformation to the operator of the power grid operation server 300.

A control unit 330 of the power grid operation server 300 manages andcontrols the operations of the PGCC 310 and the HMI 320.

The control unit 330 includes at least one processor having a dataprocessing function and a computational function. The control unit 330creates and processes a message based on a communication protocol agreedbetween the PGCC 310 and the SECC 230.

The power grid operation server 300 may consolidate grid informationcollected from the power grid 400 into grid profile and may provide thegrid profile to the SECC 230 and/or the EVCC 150.

The EV 100 and the EVSE 200 may set the charge or discharge schedule onthe basis of the grid profile provided from the power grid operationserver 300.

Also, the power grid operation server 300 may provide a proposal for thecharge or discharge schedule to the SECC 230 on the basis of the gridprofile.

When the grid profile is changed, the power grid operation server 300may inform the SECC 230 of necessity for an updated charge or dischargeschedule (or an updated energy transfer schedule).

When the power grid operation server 300 is referred to as adistribution system, the power grid operation server 300 may be a serverresponsible for voltage stability in the distribution grid.

The power grid 400 may be used as a term including a distribution systemnetwork, and the distribution system network carries electricity from atransmission grid to consumers.

The distribution system network includes medium-voltage power lines,electrical substations, low-voltage distribution wiring networks,associated equipment, and the like.

A communication protocol defining communication between the EVCC 150 andthe SECC 230 may be the same as or different from a communicationprotocol defining communication between the SECC 230 and the PGCC 310.

When the communication protocols are different, the SECC 230 may convertand process commands and/or information related to the charge ordischarge schedule received from the EVCC 150 using a communicationprotocol agreed with the PGCC 310.

Conversely, when the communication protocols are different, the SECC 230may convert and process commands and/or information related to thecharge or discharge schedule received from the PGCC 310 using acommunication protocol agreed with the EVCC 150.

The communication between the EVCC 150 and the SECC 230 may beclassified into a local communication connection and a remotecommunication connection.

FIG. 2 is a diagram illustrating a local communication connectionbetween an electric vehicle communication controller and a supplyequipment communication controller using the open systemsinterconnection (OSI) layers according to an embodiment of the presentinvention.

Referring to FIG. 2, when the EVCC 150 and the SECC 230 are locallyconnected, the EVCC 150 and the SECC 230 perform communication (21) inthe same application layer through a bridge 20.

Physical 1 Layer of the EVCC 150 performs communication (22) withPhysical 1 Layer of the bridge 20, and Physical 1 Layer of the bridge 20and Physical 1 Layer of the SECC perform communication (23).

The bridge 20, a PLC chip for processing PLC, and the SECC 230 may beincluded in a circuit implemented in the same board (substrate).

FIG. 3 is a diagram illustrating a remote communication connectionbetween an electric vehicle communication controller and a supplyequipment communication controller using the OSI layers according toanother embodiment of the present invention.

Referring to FIG. 3, for a remote communication connection between theEVCC 150 and SECC 230, a bridge 30 and a router 31 may be designedtherebetween. In this case, the bridge 30 may be optional or havemultiple bridges depending on the design architecture.

Through the bridge 30 and the router 31, the EVCC 150 and the SECC 230performs communication (32) in the same application layer.

Physical 1 Layer of the EVCC 150 and physical 1 Layer of the bridge 30perform communication (33), and Physical 2 Layer of the bridge 30 andPhysical 2 Layer of the router 31 perform communication (34). Also,Physical 3 Layer of the router 31 and Physical 3 Layer of the SECC 230perform mutual communication (35).

FIG. 4 is a diagram illustrating a communication connection between asupply equipment communication controller and a power grid communicationcontroller using the OSI layers according to still another embodiment ofthe present invention.

Referring to FIG. 4, for a communication connection between the SECC 230and the PGCC 310, a gateway 40 and a router 41 may be designedtherebetween. The designing of the router 41 may be optional.

The gateway 40, the router 41, a PLC chip, and the SECC 230 may bemounted on the same board and configured as one circuit.

The application layer of the SECC 230 performs communication withApplication 1 Layer of the gateway 40, and Application 2 Layer of thegateway 40 performs communication with the application layer of the PGCC310 through the router 41.

Physical 1 Layer of the SECC 230 performs communication with Physical 1Layer of the gateway 40, and Physical 2 Layer of the gateway 40 mayperform communication with Physical 2 Layer of the router 41. Also,Physical 3 Layer of the router 41 performs communication with Physical 3Layer of the PGCC 310.

FIG. 5 is a flowchart illustrating a discharge scenario according to anembodiment of the present invention.

Referring to FIG. 5, first, in operation 511, communication setup isperformed between the EVCC 150 and the SECC 230.

The communication setup may include procedures such as IP addressassignment, SECC discovery, TCP or TLS connection setup, and V2Gcommunication session setup.

The V2G communication session may be a session for exchanging a V2Gmessage between the EVCC 150 and the SECC 230.

The V2G message may be a message exchanged in the application layerbetween the EVCC 150 and the SECC 230.

The communication setup may further include a process in which the EVCC150 and the SECC 230 exchange information on a communication protocolversion.

Subsequently, in operation 512, when the communication setup iscompleted, identification, authentication, and authorization processesare performed between the EVCC 150 and the SECC 230.

The EVSE 200 performs authentication processing to check whether the EV100 is subject to charge or discharge. For example, the SECC 230 and theEVCC 150 exchange their IDs. The SECC 230 may deliver an ID (contractID) of an EVCC associated with its own ID (EVSE ID) to the power gridoperation server 300.

The authorization processing is started by the EVCC 150.

When the SECC 230 delivers the ID of the EVCC 150 associated with itsown ID (EVSE ID) to the power grid operation server 300, the power gridoperation server 300 may participate in the authentication andauthorization processing for the EV 100. Here, the ID of the EVCC 150may be unique identification code, a contact ID, a vehicle ID, or avehicle user ID of the EVCC 150.

Subsequently, in operation 513, when the authentication andauthorization processing is successfully completed, a process ofchecking the battery status of the EV 100 is performed.

The check of the battery status is a necessary procedure for setting upa discharge schedule. Information for the discharge schedule setup mayinclude, for example, information related to the capacity of a battery(Bat_kWh), information related to the voltage of a battery(Bat_voltage), information related to the current SOC value of a battery(Bat_SOC), and the like.

Subsequently, in operation 514, after checking the battery status, aprocess of setting up a charge or discharge schedule is performed.

The charge schedule setup may be a target setting related to charging.The target setting related to the charging may be to set a time relatedto a charge process, the amount of energy charge, a charging method,etc. The charging method setting may be to select a quick chargingmethod and/or the cheapest charging method.

The discharge schedule setup may be a target setting related todischarging. The target setting related to the discharging may be to seta time related to a discharge process, the amount of energy discharge, adischarging method, etc.

The discharging method setting may be to set a discharging method withthe highest amount (or discharge cost) that the vehicle user or theoperator (or electric provider) of the supply equipment can obtain inreturn when electric energy is delivered to the power grid 400.

Time setting related to the discharge process may be to reserve and seta discharge time. The discharge time includes a discharge start time anda discharge finish time. The setting of the amount of energy dischargemay be to set a battery current, a battery voltage, the amount ofbattery power, etc.

Subsequently, in operation 515, when the discharge schedule setup iscompleted, a discharging-related cost check process is performed. Thecost check process refers to a process of exchanging messages related toidentification, authentication, and authorization performed between theEV, the EVSE, and the power grid operation server.

The discharging-related cost is a discharge cost that the vehicle useror the operator (electric provider) of the EVSE can obtain.

The discharge cost is a cost calculated based on a discharge time andthe amount of energy discharge determined according to the dischargeschedule. When the discharging is forcibly stopped by the interventionof the vehicle user or a third party, a cost calculated when thedischarging is forcibly stopped is deducted from the discharge cost. Thethird party may be the operator (electric provider) of the EVSE or theoperation of the power grid operation server. The cost calculated whenthe discharging is forcibly stopped is referred to as a return cost.

Subsequently, in operation 516, when the discharge cost check issuccessfully completed, the EV 100 informs the EVSE 200 that it is readyfor discharging, or conversely, the EVSE 200 informs the EV 100 that itis ready for discharging.

When the EV 100 or the EVSE 200 receives a message related to thecompletion of the preparation for discharging (Gen_ready, Offgen_ready)from each other, the discharging is started.

Subsequently, in operation 517, when the discharging preparation processis successfully completed, discharging is started in which dischargeenergy is transferred from the OBC 120 of the EV 100 to the off-boardcharger 210 in the EVSE 200, and a process in which the HMI 320 of thepower grid operation server 300 displays the discharging progress isperformed.

Subsequently, a discharge stop process is performed by user interventiondischarging is in progress in operation 518A, or a discharge finishprocess is performed by a discharge schedule in operation 518B.

The discharge stop process is a process of forcibly stopping a dischargeprocess by the vehicle user, the operator of the EVSE 200, or theoperator of the power grid operation server 300 while discharging is inprogress.

The discharge stop may be initiated by executing a dischargestop-related button installed in the EVSE 200 and the power gridoperation server 300.

Alternatively, the discharge stop may be initiated by the HMIs 140, 220,and 320 in the EVSE 200 and the power grid operation server 300.

The discharge finish is different from the discharge stop in which thedischarging is forcibly stopped by external intervention in that thedischarge finish is a process of normally finishing discharging at adischarge finish time reserved according to a discharge schedule.

FIG. 6 is a sequence diagram of messages exchanged between an electricvehicle, a supply equipment, and a power grid operation server on thebasis of a discharge scenario according to an embodiment of the presentinvention and also is a sequence diagram in the case of setting up adischarge schedule in the electric vehicle.

When communication setup between the EVCC 150, the SECC 230, and thePGCC 310 is completed, the entities 120, 140, 150, 210, 230, and 300exchange messages as shown in FIG. 6.

The term “message” shown in FIG. 6 may be replaced with any one termamong “data,” “signal,” “information,” “code,” and “command.” As shownin FIGS. 2 to 4, the messages may be messages exchanged in theapplication layer, but the present invention is not limited thereto.That is, the messages shown in FIG. 6 may be defined as messagesexchanged in other layers.

Although the messages shown in FIG. 6 are arranged in a verticaldirection, this arrangement need not be construed as an arrangement forindicating the transmission order of messages transmitted from oneentity to another. Therefore, Message A may be transmitted after MessageB is transmitted first although Message A appears above Message B inFIG. 6.

Although not particularly limited, each message shown in FIG. 6 may havea message structure composed of a header and a payload. Information forpayload processing may be recorded in the header. For example, aprotocol version, a payload type, and a payload length (or a messagelength) may be recorded in the header. Application data (e.g., eachmessage shown in FIG. 6) may be recorded in the payload. Each messagerecorded in the payload may be expressed using multiple bit arrays or aflag value of “0” or “1.”

Each message shown in FIG. 6 will be described in detail below.

The power grid operation server 300 transmits messages related to thesales tariff table to an EV 100.

The messages related to the sales tariff table include Grid_time_cost,Gen_time_cost_change, Grid_day_cost, Grid_night_cost, etc.

Grid_time_cost

The message Grid_time_cost may indicate or include information relatedto a discharge cost for each time according to a local grid situation ora grid schedule. The discharge cost is a cost paid to an electricvehicle (a vehicle user) in return for performing a discharge process inwhich the electric vehicle transfers energy to a power grid via anoff-board charger.

The message Grid_time_cost is transmitted from the power grid operationserver 300 to the EV 100 via the PGCC 310, the SECC 230, and the EVCC150.

A gateway and/or a router may be additionally present between the SECC230 and the PGCC 310 in a communication path of the messageGrid_time_cost.

Hereinafter, unless otherwise specified, it is assumed that a gatewayand/or a router are additionally present in a communication path betweenthe SECC 230 and the PGCC 310.

The OBC 120 delivers the message Grid_time_cost received through theEVCC 150 to the HMI 140, and the HMI 140 displays and provides themessage Grid_time_cost to the vehicle user.

The message Grid_time_cost is utilized to set up (or create) a dischargeschedule. For example, the vehicle user may check the messageGrid_time_cost to set up an optimal discharge time (a dischargereservation time). Here, the optimal discharge time is a time at whichthe highest discharge cost can be obtained from the vehicle user.

The discharge time includes a discharge start time (Gen_start_time) anda discharge finish time (Gen_finish_time) to be described below.

Grid_time_cost_change

The message Gen_time_cost_change includes information related to avariation of a discharge cost for each time according to the local gridsituation or grid schedule.

The message Grid_time_cost_change is transmitted from the power gridoperation server 300 to the EV 100 via the PGCC 310, the SECC 230, andthe EVCC 150. The message Gen_time_cost_change is utilized to set up (orcreate) a discharge schedule.

Grid_day_cost

The message Grid_day_cost may indicate or include information related toa discharge cost during day time everyday on the basis of the local gridsituation or grid schedule.

The message Grid_day_cost is transmitted from the power grid operationserver 300 to the EV 100 via the PGCC 310, the SECC 230, and the EVCC150.

The message Grid_day_cost is utilized to set up (or create) a dischargeschedule Gen_schedule.

Grid_night_cost

The message Grid_night_cost may indicate or include information relatedto a discharge cost during night time everyday on the basis of the localgrid situation or grid schedule.

The message Grid_night_cost is transmitted from the power grid operationserver 300 to the EV 100 via the PGCC 310, the SECC 230, and the EVCC150.

The message Grid_nigh_tcost is utilized to set up (or create) adischarge schedule Gen_schedule.

The power grid operation server 300 may provide the messagesGen_time_cost, Gen_time_cost_change, Grid_day_cost, and Grid_night_costto the electric vehicle 100 individually or may consolidate the messagesGen_time_cost, Gen_time_cost_change, Grid_day_cost, and Grid_night_costinto a sales tariff table and then provide the sales tariff table to theEV 100.

Grid_energy_limit

The message Grid_energy_limit may indicate or include a limit value whenit is necessary for the power grid 400 to limit the amount of energydischarge according to the local grid situation.

The message Grid_energy_limit is transmitted from the power gridoperation server 300 to the EV 100 via the PGCC 310, the SECC 230, andthe EVCC 150.

Off_gen_day_cost

The message Off_gen_day_cost may indicate or include information relatedto a discharge cost that is set differently for each off-board charger.

The message Off_gen_day_cost is transmitted from the off-board charger210 to the EV 100 via SECC 230 and the EVCC 150.

FIG. 1 shows one off-board charger 210, but when multiple off-boardchargers are present in the EVSE 200, each off-board charger has adifferent discharge cost from the other off-board chargers.

By each off-board charger delivering the message Off_gen_day_cost to theEV 100, the EV 100 may select an appropriate off-board charger andproceed with the discharge process.

The message Off_gen_day_cost is utilized to set up (or create) adischarge schedule Gen_schedule.

The OBC 120 provides the messages Gen_time_cost, Gen_time_cost_change,Grid_day_cost, Grid_night_cost, and Off_gen_day_cost received throughthe EVCC 150 to the vehicle user through the HMI 140.

After checking the messages Gen_time_cost, Gen_time_cost_change,Grid_day_cost, Grid_night_cost, and Off_gen_day_cost displayed throughthe HMI 140, the vehicle user sets up an appropriate discharge scheduleGen_schedule. For example, the vehicle user sets an optimal dischargestart time, an optimal discharge finish time, etc.

Bat_kWh, Bat_voltage, and Bat_SOC

The messages Bat_kWh, Bat_voltage, and Bat_SOC are delivered from theBMS 160 to the HMI 140, and the HMI 140 displays and provides themessages Bat_kWh, Bat_voltage, and Bat_SOC to the vehicle user to set upthe discharge schedule. Also, the messages Bat_kWh, Bat_voltage, andBat_SOC are delivered from the BMS 160 to the OBC 120.

The message Bat_kWh may indicate or include information related to thecurrent battery capacity (current battery capacity information) of thevehicle battery 110.

The OBC 120 calculates a discharge time on the basis of the batterycapacity information. The discharge time may include a discharge starttime and a discharge finish time. Alternatively, the discharge time maybe a time taken to reach the amount of energy discharge that is set bythe vehicle user. The discharge time is utilized to set up (or create) adischarge schedule Gen_schedule.

The message Bat_voltage may indicate or include battery voltageinformation. The OBC 120 determines whether the battery voltage isabnormal using the battery voltage information, and then calculates thedischarge time.

The OBC 120 determines whether the battery voltage is abnormal at hightemperature in summer using the battery voltage information, and thedetermination result is utilized to calculate the discharge time (thedischarge start time and the discharge finish time).

The OBC 120 determines whether the battery voltage is abnormal at lowtemperature in winter using the battery voltage information, and thedetermination result is utilized to calculate the discharge time (thedischarge start time and the discharge finish time).

The message Bat_SOC may indicate or include information related to thecurrent state of charge of the vehicle battery.

The OBC 120 utilizes the information related to the current state ofcharge to calculate the discharge time (the discharge start time and thedischarge finish time).

The state of charge (SOC) is utilized as a criterion for determiningwhether the vehicle battery can be currently discharged. For example,the OBC 120 determines whether the current SOC value falls within apreset dischargeable SOC range.

When the current SOC value falls within the dischargeable SOC range thatis set differently for each season, the discharge process is started.Otherwise, the discharge process is not started.

For example, the OBC 120 checks the current SOC value to determine thecurrent SOC value falls within dischargeable SOC ranges that are set inspring and autumn. Also, the OBC 120 checks the current SOC value anddetermines whether the current SOC value falls within dischargeable SOCranges that are set in summer and winter.

Gen_energy

The message Gen_energy may indicate or include the amount of energydischarge that the OBC 120 intends to transfer to the off-board charger.

The vehicle user sets the amount of energy discharge through the HMI140.

For example, the vehicle user sets the amount of energy discharge incomprehensive consideration of the sales tariff table provided from thepower grid operation server 300, the message Off_gen_day_cost providedfrom the off-board charger, and the messages Bat_kWh, Bat_voltage, andBat_SOC provided from the BMS.

Gen_start_time

The message Gen_start_time may indicate or include a discharge starttime.

The message Gen_start_time is transmitted to the EVSE 200 or theoff-board charger 210 via the EVCC and the SECC. Also, the messageGen_start_time is transmitted to the power grid operation server 300 viathe EVCC, the SECC, and the PGCC.

The vehicle user sets a discharge start time through the HMI 140. Inthis case, similar to the setting of the amount of energy discharge, thevehicle user sets the discharge start time in comprehensiveconsideration of the sales tariff table provided from the power gridoperation server 300, the message Offchar_day_cost provided from theoff-board charger 210, and the messages Bat_kWh, Bat_voltage, andBat_SOC provided from the BMS, which are displayed from the HMI 140.

For example, after checking the messages Gen_time_cost,Gen_time_cost_change, Grid_day_cost, Grid_night_cost, andOff_gen_day_cost through the HMI 140, the vehicle user sets and reservesan optimal discharge start time with the highest discharge cost to bereceived.

In an example, the vehicle user checks a discharge cost for each daytime and for each night time through the HMI 140 and then sets andreserves a discharge start time. In another example, the vehicle userchecks a discharge cost that varies daily or hourly and sets andreserves a discharge start time.

Gen_finish_time

The message Gen_finish_time may indicate or include a discharge finishtime.

The message Gen_finish_time is transmitted to the EVSE 200 or theoff-board charger 210 via the EVCC and the SECC. Also, the messageGen_finish_time is transmitted to the power grid operation server 300via the EVCC, the SECC, and the PGCC.

The vehicle user checks, through the HMI 140, the messagesGrid_time_cost, Grid_time_cost_change, Grid_day_cost, Grid_night_cost,Off_gen_day_cost and the messages Bat_kWh, Bat_voltage, Bat_SOC receivedfrom the off-board charger 210 and/or the power grid operation server300 and then sets and reserves, through the HMI 140, an optimaldischarge finish time with the highest discharge cost to be received.

Gen_schedule

The message Gen_schedule may indicate or include dischargeschedule-related information configured to include the messagesGen_energy, Gen_start_time, and Gen_finish_time.

The message Gen_schedule is transmitted to the EVSE 200 or the off-boardcharger 210 of the EVSE 200 via the EVCC150 and the SECC 230.

Also, the message Gen_schedule is transmitted to the power gridoperation server 300 via the EVCC 150, the SECC 230, and the PGCC 310.

Authorize_code

The message Authorize_code may indicate or include authorization code ofa vehicle user. The message Authorize_code is delivered from the HMI 140to the OBC 120.

The authorization code, which is special code assigned to each vehicle,is personal information used for cost settlement.

Authorize_response

The message Authorize_response is a message transmitted from the OBC 120to the HMI 140 and is a response message to the message Authorize_code.

Data_integrity_check

The message Data_integrity_check, which is a message transmitted fromthe HMI 140 to the OBC 120, is utilized to check identification code fora data integrity check.

Cost_authorize_request

The message Cost_authorize_request, which is a message requestingauthorization for a discharge cost, is transmitted from the EVSE 200 tothe EV.

When receiving discharge schedule information Gen_schedule from the OBC120 through the SECC 230, the off-board charger 210 calculates adischarge cost Cost_calc to be paid to the vehicle user on the basis ofthe received discharge schedule information Gen_schedule.

A discharge cost may be calculated based on a set cost per 1 KW. The setcost per 1 KW may be defined a sale tariff table provided by the powergrid operation server 300. The set cost per 1 KW may be differently setbased on time, day, night, and season. For example, the set cost per 1KW may be set to be high at a time at which the amount of powerconsumption is high, and the set cost per 1 KW may be set to be low at atime at which the amount of power consumption is low.

When the set cost per 1 KW is 150 won, a discharge cost based on theamount of discharge (or the amount of energy discharge) of each vehiclemay be listed in the following Table 1.

TABLE 1 Amount of discharge Discharge dost Division (kWh) (won) EV1 101,500 EV2 15 2,250 EV3 20 3,000 Sum 6,750

Moreover, Table 1 may list a discharge cost individually calculated fromthe amount of discharge of each vehicle (individual discharge). In termsof shared economy, the amounts of discharge of vehicles discharged atthe same time may be summated, and when a summated discharge amount ishigher than or equal to a reference discharge amount (or a referenceenergy discharge amount), a discharge cost may be calculated by applyingan additional calculation cost (summated discharge).

When the reference discharge amount is 40 kWh and the summated dischargeamount is 40 kWh or more, it may be assumed that the additionalcalculation cost is 1%, and it may be assumed that the amounts ofdischarge of Table 1 is the amount of discharge is the amounts ofdischarge of three electric vehicles EV1, EV2, and EV3 discharged at thesame time.

In Table 1, when the amounts of discharge of the three electric vehiclesEV1, EV2, and EV3 are summated, a summated discharge amount may be 45kWh (=10 kWh+10 kWh+15 kWh). Therefore, a discharge cost to which anadditional calculation cost is applied by 1% may be about 6,818(=6,750+67.5 (=6,750×1%)).

Comparing the amount of discharge of each vehicle with a sum 6,750 wonof individually calculated discharge costs, a profit of about 68 won maybe additionally obtained by applying an additional calculation cost to adischarge cost, and an additionally obtained profit may return to a userof each vehicle.

Therefore, each user may receive a more cost in a method, whichcalculates a discharge cost by summating the amount of discharge of anelectric vehicle than the amounts of discharge of other electricvehicles, than a method of calculating a discharge cost on the basis ofthe amount of individual discharge.

The additional calculation cost may be differentially set based on asummated discharge amount, and for example, may be listed in thefollowing Table 2.

TABLE 2 Summated discharge amount (kWh) of amounts Additional ofdischarge of electric vehicles participating calculation cost in sumdischarge (%) 40~79 1%  80~119 1.5%  120~159 2% 160~199 2.5%  200 ormore 3%

Individual discharge to which the additional calculation cost is notapplied and sum discharge to which the additional calculation cost isapplied may be selected through the HMI 140 included in an electricvehicle.

When a user selects through the HMI 140 the sum discharge to which theadditional calculation cost is applied, the EV 100 may transmit anauthorization code Authorize_Code or a discharge schedule and a message,requesting the calculation of a discharge cost based on the sumdischarge, to the EVSE 200.

The EVSE 200 may identify electric vehicles participating in the sumdischarge, on the basis of the message, and in calculating a dischargecost of the identified electric vehicles, the addition calculation costlisted in Table 2 may be applied.

The off-board charger 210 may generate a cost authorization requestmessage Cost_authorize_request including the calculated discharge costand may transmit the cost authorization request message to the EV or theon-board charger of the EV 100 via the SECC 230 and the EVCC.

The off-board charger 210 configures the calculated discharge cost intothe cost authorization request message Cost_authorize_request andtransmits to the EV 100 or the OBC of the EV via the SECC 230 and theEVCC.

FIG. 6 shows that the off-board charger 210 calculates a discharge cost.However, the present invention is not limited thereto, and the powergrid operation server 300 may also calculate a discharge cost. In thiscase, the power grid operation server 300 may calculate a discharge coston the basis of the discharge schedule information Gen_schedule receivedthrough the SECC 230 of the EVSE 200 and may transmit the calculateddischarge cost to the EV 100 through the EVSE 200.

When receiving a cost authorization request messageCost_authorize_request from the SECC 230, the EVCC 150 of the EV 100delivers the cost authorization request message Cost_authorize_requestto the OBC 120. The OBC 120 delivers discharge cost-related informationCost_calc included in the cost authorization request messageCost_authorize_request to the HMI 140, and the HMI 140 displays thedischarge cost-related information Cost_calc to the vehicle user.

The vehicle user checks information on the discharge cost displayed fromthe HMI 140 and determines whether to authorize the discharge cost.

Cost_authorize

The message Cost_authorize is a response to the messageCost_authorize_request and is a message indicating authorization for thedischarge cost calculated by the off-board charger 210.

After receiving the authorization message Cost_authorize, the off-boardcharger 210 provides the authorization message Cost_authorize to anadministrator (electric provider or operator) of the off-board charger210 through the HMI 220.

When checking the authorization message Cost_authorize displayed fromthe HMI 220, the administrator of the off-board charger 210 startspreparing for discharging.

Gen_ready

The message Gen_ready is a message indicating that it is ready fordischarging and is a message that the OBC 120 and the off-board charger210 exchange with each other.

When the exchange of the message Gen_ready is completed, the OBC 120 andthe off-board charger 210 start the discharge process according to a setdischarge schedule Gen_schedule.

Car_energy_stop

The message Car_energy_stop is a message for the vehicle user toforcibly stop charging the EV 100 while charging the EV 100, and is amessage transmitted from the EV 100 to the EVSE 200 or to the power gridoperation server 300 via the EVSE 200.

When the vehicle user inputs a command to forcibly stop the dischargeprocess through the HMI 140, the HMI 140 delivers the messageCar_energy_stop corresponding to the command to the OBC 120, and the OBC120 transmits the message Car_energy_stop to the SECC 230 through EVCC150.

The SECC 230 delivers the message Car_energy_stop received from the EVCC150 to the off-board charger 210, and the off-board charger 210 stopsthe discharge process in response to the message Car_energy_stop.

Also, the SECC 230 transmits the message Car_energy_stop received fromthe EVCC 150 to the PGCC 310 of the power grid operation server 300 toinform the power grid operation server 300 that the charge process isstopped.

When receiving the message Car_energy_stop, the EVSE 200 and/or thepower grid operation server 300 ignore the discharge finish timedetermined according to the discharge schedule and immediately stop thedischarge process.

Meanwhile, when the vehicle user needs to immediately stop dischargingthe EV 100, the vehicle user may stop the discharge process using adischarge stop button displayed by the HMI 140 or a physical buttoninstalled in the EV 100.

Gen_cost_refund

The message Gen_cost_refund may indicate or include information relatedto a return cost added to the discharge cost received by the vehicleuser from the EVSE 200 when the discharge process of the EV 100 isforcibly stopped by the message Car_energy_stop.

The return cost may be a cost corresponding to a difference between theamount of energy discharge Gen_energy determined according to thedischarge schedule and the amount of energy discharged by the EV 100when the discharging is forcibly stopped.

Similar to the calculation of the discharge cost, the calculation of thereturn cost may be performed by the off-board charger 210 or by thepower grid operation server 300.

The calculation of the return cost may also be performed by an EV. Inthis case, an authorization procedure of the EVSE 200 or the power gridoperation server 300 is required for the return cost calculated by theEV 100.

For this authorization, for example, the EV 100 may transmit adifference cost (return cost) calculated by the EV 100 to the SECC 230through the EVCC 150 or to the PGCC 310 via the SECC 230.

The discharge stop of the vehicle battery may be initiated by therequest of the EVSE 200 and/or the power grid operation server 300rather than the EV 100.

For example, when an overload of the power grid 400 is expected (insummer), the power grid operation server 300 starts a discharge stopprocess by transmitting a discharge stop command to the EVSE 200 and theEV 100 and recovers a difference cost (or a return cost) caused by thedischarge stop process.

The message Gen_cost_refund is delivered to the HMI 140 in the EV, andthe HMI 140 displays the difference cost (return cost) returned to theEVSE 200 or the power grid operation server 300. Thus, the vehicle usermay check the difference cost (return cost).

CO₂ diminish_sum

The message CO₂ diminish_sum indicates or includes information relatedto the amount of carbon dioxide (CO₂) reduction calculated based on theamount of energy consumption of the EV 100 or a value obtained byaccumulating the amount of CO₂ reduction and is transmitted from the OBC120 of the EV 100 to the power grid operation server 300 or theoff-board charger 210 of the EVSE 200.

The OBC 120 periodically collects the amount of energy consumption ofthe EV 100 and calculates the amount of CO₂ reduction on the basis ofthe collected amount of energy consumption.

The amount of CO₂ reduction may be calculated by a conversion table or aconversion expression that represents a mapping relationship between theamount of energy consumption and the amount of CO₂ reduction. Theconversion table or the conversion expression may be provided from theEVSE 200 or the power grid operation server 300.

The amount of energy consumption, which is the consumption amount ofelectric energy charged in the vehicle battery 110, may be calculatedbased on mileage and speed and may be provided from, for example, theBMS. It will be appreciated that the OBC 120 may calculate the amount ofenergy consumption on the basis of battery information provided from theBMS 160. The amount of energy consumption may be, for example, an SOCvalue, the amount of power consumption, etc.

Also, the amount of energy consumption may include at least one of theamount of energy charge and the amount of energy discharge.

The calculation of the amount of CO₂ reduction according to the amountof energy consumption may be performed by the BMS. In this case, the BMSprovides the calculated amount of CO₂ reduction to the OBC 120.

The OBC 120 may deliver the amount of CO₂ reduction to the HMI 140, andthe HMI 140 may display and provide the amount of CO₂ reduction to thevehicle user.

The amount of CO₂ reduction is utilized to provide credit or incentiveto vehicle users who participate in CO₂ emission regulation.

For example, the amount of CO₂ reduction may be utilized to calculate anincentive cost added to a discharge cost paid to a vehicle useraccording to the amount of energy consumption of the EV 100 and/or acost deducted from a charge cost that a vehicle user has to pay to thepayment unit 240 of the EVSE 200 when charging an EV.

The calculation of the incentive cost or deduction cost may be performedby the OBC 210 or the power grid operation server 300. For example, theoff-board charger 210 may calculate the incentive cost or the deductioncost on the basis of the amount of CO₂ reduction received through theSECC 230.

The calculated incentive cost or deduction cost may be provided to theEV 100 and may be displayed through the HMI 140 of the EV 100. Thevehicle user checks the incentive cost or the deduction cost displayedthrough the HMI 140. In this case, when the calculation of the incentivecost or the deduction cost is incorrect, the EV 100 may re-request theoff-board charger 210 or the power grid operation server 300 tocalculate the cost.

FIG. 7 is a sequence diagram between an electric vehicle, a supplyequipment, and a power grid operation server according to anotherembodiment of the present invention and also is a sequence diagram inthe case of setting up a discharge schedule in the supply equipment.

When communication setup between entities 120, 140, 150, 210, 230, and300 is completed, the entities 120, 140, 150, 210, 230, and 300 exchangemessages as shown in FIG. 7.

The term “message” shown in FIG. 7 may be replaced with any one termamong “data,” “signal,” “information,” “code,” and “command.” Althoughnot particularly limited, as shown in FIGS. 2 to 4, the messages may bemessages exchanged in the application layer.

Although the messages shown in FIG. 7 are arranged in a verticaldirection, this arrangement need not be construed as an arrangement forindicating the transmission order of messages. Therefore, depending onthe design, Message A may be transmitted after Message B is transmittedfirst although Message A appears above Message B.

Similar to the message structure described with reference to FIG. 6, themessage structure of FIG. 7 may be composed of a header and a payload.The description of the message structure shown in FIG. 7 is replacedwith the description of the message structure described with referenceto FIG. 6.

Each message shown in FIG. 7 will be described in detail below.

Authorize_request

The message Authorize_request may indicate or include informationrelated to an authentication authorization request. The informationrelated to the authentication authorization request may be configured toinclude identification information ID of the off-board charger 210 oridentification information EVSE ID of the EVSE 200.

An operator (electric provider) of the EVSE 200 inputs the informationrelated to the authentication authorization request through the HMI 220of the EVSE 200.

The off-board charger 210 delivers the information related to theauthentication authorization request to the SECC 230, and the SECC 230configures the information related to the authentication authorizationrequest into the message Authorize_request according to a communicationprotocol agreed with the EVCC 150 and transmits the messageAuthorize_request to the EVCC 150.

The EVCC 150 delivers the message Authorize_request received from theSECC 230 to the OBC 120 of the EV 100, and the OBC 120 delivers themessage Authorize_request to the HMI 140 in the EV 100.

The HMI 140 in the EV 100 displays the message Authorize_requestdelivered from the OBC 120 and provides the information related to theauthentication authorization request made by the supply equipment to thevehicle user.

Authoriz_erequest_tryout

The message Authorize_request_tryout is a message re-requestingauthentication authorization from the EV 100.

Authorize_OK_res

The message Authorize_OK_res is a response message to the messageAuthorize_request and is a message allowing the authenticationauthorization requested by the EVSE 200 or the off-board charger 210 ofthe EVSE 200.

The off-board charger 210 starts the discharge process when receivingthe message Authorize_OK_res from the EV.

Authorize_NOK_res

The message Authorize_NOK_res is a response message to the messageAuthorize_request and is a message disallowing the authenticationauthorization request of the off-board charger 210 in case ofauthentication failure.

When receiving the message Authorize_NOK_res from the EV 100, the EVSE200 terminates the authorization process or transmits the messageAuthorize_request_tryout to the EV to re-request authenticationauthorization.

Bat_kWh, Bat_voltage, Bat_SOC

The messages Bat_kWh, Bat_voltage, and Bat_SOC are the same as themessages Bat_kWh, Bat_voltage, and Bat_SOC described with reference toFIG. 6.

The messages Bat_kWh, Bat_voltage, and Bat_SOC are utilized for thesetup of a discharge schedule performed in the EVSE 200 and aredisplayed through the HMI 220 of the EVSE 200.

The operator (electric provider) of the EVSE 200 sets up a dischargeschedule on the basis of the messages Bat_kWh, Bat_voltage, Bat_SOCdisplayed from the HMI 220.

The discharge schedule setup of the EVSE 200 may also be performed bythe vehicle user rather than the operator (or the electric provider) ofthe EVSE 200.

For example, after the vehicle user moves to the EVSE 200, the vehicleuser may set up the discharge schedule by inputting information relatedto the discharge schedule to the HMI 220 of the EVSE 200.

Offgen_energy

The message Offgen_energy, which is a message indicating or includingthe amount of energy discharge of the off-board charger 210, istransmitted from the EVSE 200 to the EV 100.

The vehicle user or the operator (electric provider) of the EVSE 200sets the amount of energy discharge on the basis of the sales tarifftable provided from the power grid operation server 300 and/or themessages Bat_kWh, Bat_voltage, and Bat_SOC provided from the EV 100, andinputs the amount of energy discharge to the HMI 220.

The sales tariff table includes the messages Grid_time_cost,Grid_time_cost_change, Grid_day_cost, and Grid_night_cost.

The HMI 220 delivers the input amount of energy discharge to theoff-board charger 210, and the off-board charger 210 delivers the amountof energy discharge delivered from the HMI 220 to the SECC 230.

The SECC 230 configures the amount of energy discharge transferred fromthe HMI 220 into the message Offgen_energy on the basis of acommunication protocol agreed with the EVCC 150 and transmits themessage Off_gen_energy to the EVCC 150.

The amount of energy discharge, which is the amount of energy deliveredby the off-board charger 210 to the power grid 400, is utilized asinformation for setting up the discharge schedule.

The operator of the EVSE 200 or the vehicle user of the EV 100 sets themost advantageous amount of energy discharge on the basis of the salestariff table.

The setting of the amount of energy discharge may also be performed bythe power grid operation server 300. In this case, the power gridoperation server 300 may receive messages or information necessary toset the amount of energy discharge from the EVSE 200 or from the EV 100via the EVSE 200.

Off_gen_start_time

The message Off_gen_start_time indicates or includes a discharge starttime of the off-board charger 210 and is transmitted from the EVSE 200to the EV 100. The message Off_gen_start_time may be one of the piecesof information for setting the discharge schedule.

The operator of the EVSE 200 may reserve and set the discharge starttime of the off-board charger 210 using the HMI 220. At this time, theoperator of the EVSE 200 may reserve and set an optimal discharge starttime on the basis of the sales tariff table provided from the power gridoperation server 300 and the messages Bat_kWh, Bat_voltage, and Bat_SOCreceived through the SECC 230. Here, the optimal discharge start timemay be a time at which the vehicle user or the operator of the EVSE 200can receive the highest discharge cost.

The setting of the discharge start time may be performed not by theoperator of the EVSE 200 but by the vehicle user. For example, aftermoving to the EVSE 200, the vehicle user may set the optimal dischargestart time using the HMI 220 of the EVSE 200.

The setting of the discharge start time may also be performed by thepower grid operation server 300. In this case, the power grid operationserver 300 may receive messages or information necessary to set thedischarge start time from the EVSE 200 or from the EV 100 via the EVSE200.

Off_gen_finish_time

The message Off_gen_finish_time indicates or includes a discharge finishtime of the off-board charger 210 and is transmitted from the EVSE 200to the EV 100. The discharge finish time may be one of the pieces ofinformation constituting the discharge schedule.

The message Off_gen_finish_time may be one of the pieces of informationfor setting the discharge schedule.

The operator of the EVSE 200 may reserve and set the discharge finishtime of the off-board charger 210 using the HMI 220. At this time, theoperator of the EVSE 200 may reserve and set the discharge finish timeon the basis of the sales tariff table provided from the power gridoperation server 300 and the messages Bat_kWh, Bat_voltage, and Bat_SOCprovided from the EV 100.

The setting of the discharge finish time may be performed not by theoperator of the EVSE 200 but by the vehicle user. For example, aftermoving to the EVSE 200, the vehicle user may set the discharge starttime using the HMI 220 of the EVSE 200.

The setting of the discharge finish time may also be performed by thepower grid operation server 300. In this case, the power grid operationserver 300 may receive messages or information necessary to set thedischarge finish time from the EVSE 200 or from the EV 100 via the EVSE200.

The off-board charger 210 configures a discharge scheduleOffgen_schedule based on the messages Off_gen_energy,Off_gen_start_time, and Off_gen_finish_time input through the HMI 220.

The off-board charger 210 transmits the discharge scheduleOff_gen_schedule to the EV 100 through the SECC 230. FIG. 7 illustratesan example in which the off-board charger 210 transmits the dischargeschedule Off_gen_schedule to the EV 100, but the off-board charger 210may transmit the discharge schedule Off_gen_schedule to the power gridoperation server 300.

The HMI 140 of the EV 100 displays the discharge scheduleOff_gen_schedule received from the EVSE 200 so that the vehicle user cancheck the discharge schedule Off_gen_schedule.

The HMI 320 of the power grid operation server 300 displays thedischarge schedule Off_gen_schedule received from the EVSE 200 so thatthe operator of the power grid operation server 300 can check thedischarge schedule Off_gen_schedule.

Cost_calc

The message Cost_calc indicates or includes a discharge cost calculatedbased on the discharge schedule set by EVSE 200 and is transmitted fromthe off-board charger 210 to the power grid operation server 300 and/orthe EV 100.

The discharge cost may be a cost paid to the operator of the EVSE 200 inreturn for the EVSE 200 transferring energy to the power grid operationserver 300 or a cost paid to the vehicle user of the EV 100 in returnfor the EV 100 transferring energy to the power grid operation server300 via the EVSE.

The cost paid to the vehicle user may be a portion of the cost paid tothe operator of the EVSE 200. The calculation of the discharge cost mayalso be performed by the power grid operation server 300.

When the power grid operation server 300 calculates a discharge cost,the power grid operation server 300 transmits the calculated dischargecost to the EVSE 200 or to the EV via the EVSE 200.

Cost_authorize_request

The message Cost_authorize_request, which is a message requestingauthorization for a calculated discharge cost, is transmitted from theEVSE 200 to the EV 100.

When the power grid operation server 300 calculates a discharge cost,the message Cost_authorize_request is transmitted to the EVSE 200 or tothe EV 100 via the EVSE 200.

Cost_Authorize_OK_res

The message Cost_Authorize_OK_res is a response message to the messageCost_authorize_request and is an authorization message for a dischargecost. The message Cost_Authorize_OK_res is transmitted from the EV 100to the EVSE 200.

Cost_Authorize_NOK_res

The message Cost_Authorize_NOK_res is a response message to the messageCost_authorize_request and is a message disallowing the authorizationfor the discharge cost. The message Cost_Authorize_OK_res is transmittedfrom the EV 100 to the EVSE 200.

Off_gen_ready

The message Off_gen_ready, which is a message informing the electricvehicle 100 that the EVSE 200 is ready for discharging, is transmittedfrom the EVSE 200 to the EV 100.

The OBC 120 of the EV 100 starts a discharge process and delivers themessage Off_gen_ready to the HMI 140 of the EV 100 when the messageOff_gen_ready is received from the EVSE 200 through the EVCC 150.

When the HMI 140 displays that the off-board charger 210 is ready fordischarging, the vehicle user commands the OBC 120 to start dischargingusing the HMI 140.

The message Off_gen_ready may also be transmitted to the power gridoperation server 300 to inform the power grid operation server 300 thatthe off-board charger 210 is ready for discharging.

Off_gen_energy_stop

The message Off_gen_energy_stop, which is a message for forciblystopping the discharge process according to the intervention of thevehicle user or the operator of the EVSE 200 while the discharging is inprogress, is transmitted from the EVSE 200 to the EV 100 and/or thepower grid operation server 300.

The forcible stop of the discharge process may be performed by the HMI220 of the EVSE 200. The vehicle user may forcibly stop the dischargeprocess using the HMI 220 of the EVSE 200.

The forcible stop of the discharge process may also be performed by theoperator of the power grid operation server 300, and in this case, thepower grid operation server 300 transmits the messageOff_gen_energy_stop to the EVSE 200 and/or the EV 100.

Off_gen_Cost_refund

The message Off_gen_Cost_refund may indicate or include a return costindicating the difference between a discharge cost calculated based onthe discharge finish time (Off_gen_finish_time) set and reserved by thevehicle user of the EV or the operator of the EVSE and a discharge costcalculated based on a discharge finish time when the discharge processof the EV 100 is forcibly stopped by the operator of the EVSE 200.

The return cost is a cost obtained by deducting a discharge costcalculated until the discharge process is forcibly stopped (thedischarge stop time) from a discharge cost initially calculatedaccording to the forcible stop of the discharge process.

The message Off_gen_Cost_refund is transmitted to the EV 100 and thepower grid operation server 300 and then displayed by the HMI 140 of theEV 100 and the HMI 320 of the power grid operation server 300.

Although not shown in FIG. 7, the EVSE 200 and the EV 100 may exchangemessages related to the authorization procedure for the return cost.Similarly, the EVSE 200 and the power grid operation server 300 mayexchange messages related to the authorization procedure for the returncost.

Off_gen_CO₂ diminish_sum

The message Off_gen_CO₂ diminish_sum indicates or includes informationrelated to the amount of CO₂ reduction calculated based on the amount ofenergy consumption (the amount of electricity consumption) of theoff-board charger 210 or a value of accumulating the amount of CO₂reduction and is transmitted from the EVSE 200 to the EV 100.

The off-board charger 210 periodically collects the amount of energyconsumption of the EV 100 or the amount of energy consumption of theoff-board charger 210 and calculates the amount of CO₂ reduction on thebasis of the collected amount of energy consumption.

The amount of CO₂ reduction may be calculated by a conversion table or aconversion expression that represents a mapping relationship between theamount of energy consumption and the amount of CO₂ reduction. Theconversion table or the conversion expression may be provided from thepower grid operation server 300.

The conversion table or the conversion expression may be included in asales tariff table provided by the power grid operation server 300.

The amount of energy consumption of the off-board charger 210 mayinclude at least one of the amount of energy that the off-board charger210 transfers to the OBC 120 of the EV 100 (the charging of the EV), theamount of energy that the off-board charger 210 receives from the OBC120 of the EV 210 (the discharging of the EV), and the amount of energythat the off-board charger 210 transfers to the power grid.

Information related to the amount of CO₂ reduction is transmitted to theHMI 140 of the EV 100 and the HMI 320 of the power grid operation server300, and the vehicle user and the operator or the power grid operationserver 300 are informed of the information related to the amount of CO₂reduction.

The amount of CO₂ reduction is utilized to calculate credit or anincentive cost for vehicle users or operators of the EVSE 200 whoparticipate in CO₂ emission regulation.

For example, the amount of CO₂ reduction may be utilized to calculate anincentive cost added to a discharge cost paid to the vehicle user or theoperator of the EVSE and/or a cost deducted from a charge cost that thevehicle user has to pay when the EV is charged.

Also, the amount of CO₂ reduction may be utilized to calculate anincentive cost added to a cost paid to the operator of the EVSE 200 onthe basis of the amount of energy consumption of the off-board charger210.

Off_gen_energy_calculation

The message Off_gen_energy_calculation indicates or includes informationrelated to the amount of energy consumption of the off-board charger 210and is delivered to the power grid operation server 300.

The power grid operation server 300 checks the amount of energyconsumption of the off-board charger 210 through the messageOff_gen_energy_calculation, and the message Off_gen_energy_calculationis utilized to calculate a cost corresponding to the amount of energyconsumption and a cost to be returned from the power grid to the EVSE200 or the EV 100.

As described above, by defining a discharging-related message exchangedbetween an electric vehicle, a supply equipment, and a power grid, it ispossible to establish an efficient billing policy for each time, andalso it is possible to efficiently operate the power grid. Also, it ispossible to provide credit or incentive to a vehicle user and anoperator of a supply equipment that participate in CO₂ emissionregulation.

As described above, a discharging-related message exchanged between anelectric vehicle, a supply equipment, and a power grid may be defined,and thus, an efficient billing policy for each time may be established.

The scope of the present invention should be defined not by the detaileddescription but by the appended claims, and all differences fallingwithin a scope equivalent to the claims should be construed as beingencompassed by the present invention.

The battery charging apparatus 120, battery charging apparatus 1912, andother apparatuses, devices, units, modules, and components describedherein are implemented by hardware components. Examples of hardwarecomponents that may be used to perform the operations described in thisapplication where appropriate include controllers, sensors, generators,drivers, memories, comparators, arithmetic logic units, adders,subtractors, multipliers, dividers, integrators, and any otherelectronic components configured to perform the operations described inthis application. In other examples, one or more of the hardwarecomponents that perform the operations described in this application areimplemented by computing hardware, for example, by one or moreprocessors or computers. A processor or computer may be implemented byone or more processing elements, such as an array of logic gates, acontroller and an arithmetic logic unit, a digital signal processor, amicrocomputer, a programmable logic controller, a field-programmablegate array, a programmable logic array, a microprocessor, or any otherdevice or combination of devices that is configured to respond to andexecute instructions in a defined manner to achieve a desired result. Inone example, a processor or computer includes, or is connected to, oneor more memories storing instructions or software that are executed bythe processor or computer. Hardware components implemented by aprocessor or computer may execute instructions or software, such as anoperating system (OS) and one or more software applications that run onthe OS, to perform the operations described in this application. Thehardware components may also access, manipulate, process, create, andstore data in response to execution of the instructions or software. Forsimplicity, the singular term “processor” or “computer” may be used inthe description of the examples described in this application, but inother examples multiple processors or computers may be used, or aprocessor or computer may include multiple processing elements, ormultiple types of processing elements, or both. For example, a singlehardware component or two or more hardware components may be implementedby a single processor, or two or more processors, or a processor and acontroller. One or more hardware components may be implemented by one ormore processors, or a processor and a controller, and one or more otherhardware components may be implemented by one or more other processors,or another processor and another controller. One or more processors, ora processor and a controller, may implement a single hardware component,or two or more hardware components. A hardware component may have anyone or more of different processing configurations, examples of whichinclude a single processor, independent processors, parallel processors,single-instruction single-data (SISD) multiprocessing,single-instruction multiple-data (SIMD) multiprocessing,multiple-instruction single-data (MISD) multiprocessing,multiple-instruction multiple-data (MIMD) multiprocessing, a controllerand an arithmetic logic unit (ALU), a DSP, a microcomputer, anapplication-specific integrated circuit (ASIC), a field programmablegate array (FPGA), a programmable logic unit (PLU), a central processingunit (CPU), a graphics processing unit (GPU), a neural processing unit(NPU), or any other device capable of responding to and executinginstructions in a defined manner.

The methods that perform the operations described in this applicationare performed by computing hardware, for example, by one or moreprocessors or computers, implemented as described above executinginstructions or software to perform the operations described in thisapplication that are performed by the methods. For example, a singleoperation or two or more operations may be performed by a singleprocessor, or two or more processors, or a processor and a controller.One or more operations may be performed by one or more processors, or aprocessor and a controller, and one or more other operations may beperformed by one or more other processors, or another processor andanother controller. One or more processors, or a processor and acontroller, may perform a single operation, or two or more operations.

Instructions or software to control a processor or computer to implementthe hardware components and perform the methods as described above arewritten as computer programs, code segments, instructions or anycombination thereof, for individually or collectively instructing orconfiguring the processor or computer to operate as a machine orspecial-purpose computer to perform the operations performed by thehardware components and the methods as described above. In one example,the instructions or software include machine code that is directlyexecuted by the processor or computer, such as machine code produced bya compiler. In an example, the instructions or software includes atleast one of an applet, a dynamic link library (DLL), middleware,firmware, a device driver, an application program storing the method ofcommunicating between an electric vehicle, a supply equipment, and apower grid operation server that monitors a power grid. In anotherexample, the instructions or software include higher-level code that isexecuted by the processor or computer using an interpreter. Programmersof ordinary skill in the art can readily write the instructions orsoftware based on the block diagrams and the flow charts illustrated inthe drawings and the corresponding descriptions in the specification,which disclose algorithms for performing the operations performed by thehardware components and the methods as described above.

The instructions or software to control a processor or computer toimplement the hardware components and perform the methods as describedabove, and any associated data, data files, and data structures, arerecorded, stored, or fixed in or on one or more non-transitorycomputer-readable storage media. Examples of a non-transitorycomputer-readable storage medium include read-only memory (ROM),random-access programmable read only memory (PROM), electricallyerasable programmable read-only memory (EEPROM), random-access memory(RAM), magnetic RAM (MRAM), spin-transfer torque(STT)-MRAM, staticrandom-access memory (SRAM), thyristor RAM (T-RAM), zero capacitor RAM(Z-RAM), twin transistor RAM (TTRAM), conductive bridging RAM(CBRAM),ferroelectric RAM (FeRAM), phase change RAM (PRAM), resistive RAM(RRAM),nanotube RRAM, polymer RAM (PoRAM), nano floating gate Memory(NFGM),holographic memory, molecular electronic memory device), insulatorresistance change memory, dynamic random access memory (DRAM), staticrandom access memory (SRAM), flash memory, non-volatile memory, CD-ROMs,CD−Rs, CD+Rs, CD−RWs, CD+RWs, DVD−ROMs, DVD−Rs, DVD+Rs, DVD−RWs,DVD+RWs, DVD−RAMs, BD−ROMs, BD−Rs, BD−R LTHs, BD-REs, blue-ray oroptical disk storage, hard disk drive (HDD), solid state drive (SSD),flash memory, a card type memory such as multimedia card micro or a card(for example, secure digital (SD) or extreme digital (XD)), magnetictapes, floppy disks, magneto-optical data storage devices, optical datastorage devices, hard disks, solid-state disks, and any other devicethat is configured to store the instructions or software and anyassociated data, data files, and data structures in a non-transitorymanner and providing the instructions or software and any associateddata, data files, and data structures to a processor or computer so thatthe processor or computer can execute the instructions. In an example,the instructions or software and any associated data, data files, anddata structures are distributed over network-coupled computer systems sothat the instructions and software and any associated data, data files,and data structures are stored, accessed, and executed in a distributedfashion by the one or more processors or computers.

While this disclosure includes specific examples, it will be apparentafter an understanding of the disclosure of this application thatvarious changes in form and details may be made in these exampleswithout departing from the spirit and scope of the claims and theirequivalents. The examples described herein are to be considered in adescriptive sense only, and not for purposes of limitation. Descriptionsof features or aspects in each example are to be considered as beingapplicable to similar features or aspects in other examples. Suitableresults may be achieved if the described techniques are performed in adifferent order, and/or if components in a described system,architecture, device, or circuit are combined in a different manner,and/or replaced or supplemented by other components or theirequivalents. Therefore, the scope of the disclosure is defined not bythe detailed description, but by the claims and their equivalents, andall variations within the scope of the claims and their equivalents areto be construed as being included in the disclosure.

What is claimed is:
 1. A method of communicating between an electricvehicle, a supply equipment, and a power grid operation server thatmonitors a power grid, the method comprising: transmitting, by anelectric vehicle communication controller of the electric vehicle, adischarge schedule comprising an amount of energy discharge, a dischargestart time, and a discharge finish time to a supply equipmentcommunication controller of the supply equipment or a power gridcommunication controller of the power grid operation server; andreceiving a discharge cost calculated according to the dischargeschedule from the supply equipment communication controller or the powergrid communication controller, wherein the discharge cost comprises anadditional calculation cost, in response to a sum of the amount ofenergy discharge of the electric vehicle and an amount of energydischarge of another electric vehicle being greater than or equal to areference energy discharge amount.
 2. The method of claim 1, furthercomprising setting up the discharge schedule in the electric vehicleprior to the transmitting of the discharge schedule, wherein the settingup of the discharge schedule comprises setting a discharge start timeand a discharge finish time on the basis of battery capacityinformation, battery voltage information, and state-of-chargeinformation.
 3. The method of claim 1, wherein the transmitting of thedischarge schedule comprises transmitting a message for calculation ofthe discharge cost, to the supply equipment communication controller ofthe supply equipment or the power grid communication controller of thepower grid operation server on the basis of the sum of the amount ofenergy discharge of the electric vehicle and the amount of energydischarge of the another electric vehicle.
 4. The method of claim 1,wherein the additional calculation cost is varied based on the sum ofthe amount of energy discharge of the electric vehicle and the amount ofenergy discharge of the another electric vehicle.
 5. The method of claim1, further comprising: transmitting an authorization message for thedischarge cost to the supply equipment communication controller or thepower grid communication controller using the electric vehiclecommunication controller; and transmitting a message, indicating that adischarge process is forcibly stopped, in response to the dischargeprocess being stopped prior to the discharge finish time by an user ofthe vehicle , to the supply equipment communication controller or thepower grid communication controller using the electric vehiclecommunication controller.
 6. The method of claim 5, further comprising:receiving, from the supply equipment communication controller or thepower grid communication controller, a message indicating a return costof a difference between a discharge cost calculated based on thedischarge finish time and a discharge cost calculated when the dischargeis forcibly stopped, in response to the discharge process being forciblystopped.
 7. A method of communicating between an electric vehicle, asupply equipment, and a power grid operation server that monitors apower grid, the method comprising: transmitting, by a supply equipmentcommunication controller embedded in the supply equipment, a dischargecost based on a discharge schedule of the electric vehicle to anelectric vehicle communication controller embedded in the electricvehicle; transmitting a message related to an authorization request forthe discharge cost to the electric vehicle communication controllerusing the supply equipment communication controller; and receiving, atthe supply equipment communication controller, an authorization messagefor the discharge cost from the electric vehicle communicationcontroller, wherein the discharge cost comprises an additionalcalculation cost, in response to a sum of the amount of energy dischargeof the electric vehicle and an amount of energy discharge of anotherelectric vehicle being greater than or equal to a reference energydischarge amount.
 8. The method of claim 7, further comprising settingup the discharge schedule in the supply equipment prior to thetransmitting of the discharge cost based on the discharge schedule,wherein the setting up of the discharge schedule is based on batterycapacity information, battery voltage information, and state-of-chargeinformation received from the electric vehicle communication controllerand a sales tariff table received from a power grid communicationcontroller of the power grid operation server.
 9. The method of claim 7,further comprising setting up the discharge schedule in the supplyequipment prior to the transmitting of the discharge cost, wherein thedischarge schedule comprises the amount of energy discharge, a dischargestart time, and a discharge finish time.
 10. The method of claim 9,further comprising, after the receiving of the authorization message forthe discharge cost, transmitting, to the supply equipment communicationcontroller and a power grid communication controller of the power gridoperation server, a message indicating that the discharge process isforcibly stopped by an operator of the supply equipment.
 11. The methodof claim 10, further comprising: transmitting, from the electric vehiclecommunication controller or the power grid communication controller, amessage indicating a return cost of a difference between a dischargecost calculated based on the discharge finish time and a cost calculatedbased on a finish time when the discharge is forcibly stopped, inresponse to the discharge process being forcibly stopped.
 12. The methodof claim 7, further comprising: calculating an amount of carbon dioxidereduction on the basis of the amount of energy consumption of anoff-board charger of the supply equipment using the supply equipmentcommunication controller; and transmitting information related to theamount of carbon dioxide reduction to the electric vehicle communicationcontroller and the power grid communication controller.